The present invention relates to a semiconductor device, and a resistance measuring system and a pressure instrumentation device each including the semiconductor device and, for example, to a semiconductor device suitable for suppressing increase of a circuit scale, and a resistance measuring system and a pressure instrumentation device each including the semiconductor device.
An instrumentation device that measures a pressure received from a measurement object, such as a scale to measure human weight, measures a change amount of a resistance value of a pressure-sensitive resistance element whose resistance value changes according to pressure change, and calculates a pressure (for example, weight) of the measurement object based on a measurement result of the change amount.
In this instrumentation device, for example, abridge circuit including four resistance elements including the pressure-sensitive resistance element is used as a pressure sensor. In this bridge circuit, the change amount of the resistance value of the pressure-sensitive resistance element appears as a potential difference between a first and a second measurement nodes of the bridge circuit.
A related technology is disclosed in Japanese Patent No. 3959828 Specification. A configuration disclosed in Japanese Patent No. 3959828 Specification includes: a resistance bridge circuit including a pressure-sensitive resistor whose resistance value changes by pressure change; an amplifier circuit that amplifies a potential difference of two voltage measuring points of the resistance bridge circuit generated according to a change amount of the resistance value of the pressure-sensitive resistor; and a voltage measuring circuit that measures an output voltage of the amplifier circuit.